Mark Giampapa et al. (Mark Giampapa, Thomas Gooding, Todd Inglett, Robert W. Wisniewski. Experiences with a lightweight supercomputer kernel: Lessons learned from Blue Gene's CNK. Proceedings of the 2010 ACM/IEEE International Conference for High Performance Computing (SC10). New Orleans, La. November 2010) outlines the different approaches taken by high performance computing (HPC) operating system kernels. The kernels fall into a spectrum defined at one end by Light-Weight Kernels (LWKs) and at the other end by Full-Weight Kernels (FWKs). Generally, LWKs such as Compute Node Kernel (CNK) from IBM® Corporation, Armonk, N.Y., provide higher performance and scalability than FWKs such as Linux but less functionality. LWKs achieve higher performance and scalability because they give applications direct access to physical resources. FWKs maintain ownership of physical resources and arbitrate access among many applications. LWKs have less functionality than FWKs because LWKs are specialized.
Linux is an example of FWK that runs on many different platforms and has a large developer base. There have been attempts to bridge the gaps between LWKs and FWKs. These approaches may fall into two categories: (1) add FWK functionality to an LWK; and (2) improve FWK performance for HPC applications. Application performance has many aspects including efficiency, scalability, and reliability. In the present disclosure, performance refers to overall application performance, measured by time to completion.